This invention relates to apparatus for the mechanical harvesting of grapes and more particularly to the type of harvester having a mobile frame adapted to straddle a plant, the harvester having opposed shaker elements mounted thereon to engage the plant therebetween and having mechanism to reciprocate the shaker elements horizontally back and forth and in unison to shake the plant and cause the ripe fruit thereon to be removed.
In order to protect the plant from undue damage as it is being shaken, the shaker elements should be supported on the frame so that the movement of the shaker elements is confined to a horizontal plane as they are reciprocated. If the shaker elements move vertically as they are reciprocated they will rub up and down on the plant, causing abrasion thereof. It is conventional practice at the present time to mount the shaker members on horizontal support members and to provide elongated horizontal sleeves on the frame in which the support members are telescopically received. Such an arrangement does serve to confine the shaker member supports so that only horizontal movement of the shaker member results. However, it has been found that the telescopic type of shaker support arrangement is not fully satisfactory. In many instances the loading imposed on the shaker element support by the shaker element will have a component transverse to the axis of the support and the sleeve in which it is telescopically secured. Such transverse force component will cause binding between the support and sleeve which results in a decrease in mechanical efficiency and an increase in wear of the support and sleeve.
Another problem with the telescopic type of shaker element support is that if the fruit has a high percentage of juice, as is the case with grapes, juice released from the fruit during harvesting will accumulate on the shaker element support members, and get into the sleeve, causing them to become sticky. As a consequence increased power is required to overcome the drag between relatively moving sticky elements.
It is the principal object of the invention to provide a relatively non-binding support structure for shaker elements which will confine movement of the shaker elements to a horizontal plane. It is a further object to provide such a support which has no interengaged surfaces that move relatively to each other so that relative movement of the support structure elements will not be impeded by an accumulation of sticky juice thereon.